Various methods are known for fabrication of a CMC structure. A CMC structure can be fabricated by melt infiltration (MI). Using MI, a preform can be placed in a chamber and arranged to be in contact with a source of liquid silicon. Liquid silicon can react with material of the preform. A CMC structure can also be fabricated using chemical vapor infiltration (CVI). For performance of CVI, a preform can be placed in a vapor chamber to cause a reaction between vapor of the chamber and material of the preform. A CMC structure can also be fabricated using polymer impregnation and pyrolysis (PIP). For performance of PIP, polymeric silicon carbide precursor can be used to infiltrate a fibrous preform. A CMC structure can also be fabricated using a combination of processes.
CMC structures are subject to damage during operation. For example CMC structures can come in contact with rigid objects and can become pierced or otherwise damaged.